A known fluorescence endoscope device in the related art radiates excitation light, which generates fluorescence by exciting a fluorescent agent accumulated specifically in a lesion, such as cancer cells, onto an observation site that is administered the fluorescent agent. The fluorescence endoscope device photographs the generated fluorescence so as to acquire a fluorescence image having high luminance in the lesion (for example, see Patent Literature 1). The fluorescence endoscope device discussed in Patent Literature 1 divides the fluorescence image based on the intensity of the fluorescence generated in the observation site irradiated with the excitation light by a reference image based on the intensity of return light returning from the same observation site irradiated with reference light so as to correct a variation in fluorescence intensity, which is dependent on the observation distance, the observation angle, and the like, in the fluorescence image.